I just gave all of my postdocs a $10,000-a-year raise.
My two current postdocs all got a $10k raise over their current salary, and the four postdocs coming on board over the next 6 months will start at $10k over the NIH base salary we pay them already. (This means that my starting postdocs will get something like $52k/year, plus benefits.)
I already pay most of my grad students more than I'm required to by UC Davis regulations. While I'm a pretty strong believer that graduate school is school, and that it's pretty good training (see Claus Wilke's extended discussion here), there's something to be said for enabling them to think more about their work and less about whether or not they can afford a slightly more comfortable life. (I pay all my grad students the same salary, independent of graduate program; see below.)
Why did I increase the postdoc salaries now? I've been thinking about it for a while, but the main reason that motivated me to do the paperwork was the change in US labor regulations. There's the cold-blooded calculation that, hey, I don't want to pay overtime; but if it were just that, I could have given smaller raises to my existing postdocs. A bigger factor is that I really don't want the postdocs to have to think about tracking their time. I also hope it will decrease postdoc turnover, which can be a real problem: it takes a lot of time to recruit a new person to the lab, and if it takes a year to recruit a postdoc and they leave sooner because the salary sucks, well, that's really a net loss to me.
More broadly, I view my job as flying cover for my employees. If they worry a little bit less because of a (let's face it) measly $10k, well, so much the better.
A while ago I decided to pay all my postdocs on the same scale; there are some people who are good at negotiating and asking, and others who aren't, and it's baldly unfair to listen more to the former. (I've had people who pushed for a raise every 6 months; I've had other people who offered to pay me back by personal check when they were out sick for a week.) I'm also really uncomfortable trying to judge a person's personal need - sure, one postdoc may have a family, and another postdoc may look free as a bird and capable of living out of the office (which has also happened due to low pay...), but everyone's lives are more complicated than they appear, and it's not my place to get that involved. So paying everyone the same salary and explaining that up front reduces any friction that might arise there, I think.
There's also the fact that I can afford it at the moment, between my startup and my Moore Foundation grant. The $10k/person increase means that I'm paying somewhere around $80k extra per year, once you include the increase in benefits -- basically, an entire additional postdoc's salary. But being the world's worst manager, I'm not sure how I will deal with a lab with 9 people in it; a 10th would probably not have helped there. So maybe it's not such a bad thing to avoid hiring one more person :). And in the future I will simply budget it into grants. (I do have one grant out in review at the moment where I underbudgeted; if I get it, I'll have to supplement that with my startup.)
The interesting thing is that I didn't realize how large a salary many of my future postdocs were turning down. In order to justify the raise to the admins, I asked for information on other offers the postdocs had received - I'd heard that some of them had turned down larger salaries, but hadn't asked for details before. Two of my future postdocs had offers in the $80k range; another was leaving a postdoc that paid north of $60k (not uncommon in some fields) to come to my lab. I'm somewhat surprised (and frankly humbled) that they were planning to come to my lab before this raise; even with this raise, I'm not approaching what they'd already been offered!
There are some downsides for the postdocs here (although I think they're pretty mild, all things considered). First, I won't have as much unbudgeted cash lying around, so supply and travel expenditures will be a bit more constrained. Second, I can't afford to keep them all on for quite as long now, so some postdoc jobs may end sooner than they otherwise would have. Third, if they want to transition to a new postdoc at UC Davis, they will probably have to find someone willing to pay them the extra money - it's very hard to lower someone's salary within an institution. (I don't expect this to be a problem, but it's an issue to consider.)
There are also some downsides for me that I don't think my employees always appreciate, too. I worry a lot - like, an awful lot - about money. I'm deathly afraid of overpromising employment and having to lay off a postdoc before they have a next step, or, worse, move a grad student to a lot of TAing. So this salary increase puts me a little bit more on edge, and makes me think more about writing grants, and less about research and other, more pleasant things. I can't help but resent that a teensy bit. On the flip side, that is my job and all things considered I'm at a pretty awesome place in a pretty awesome gig so shrug.
There may be other downsides I hadn't considered - there usually are ;) -- and upsides as well. I'll follow up if anything interesting happens.